Behavioral Guidance of Adult American Shad Using Underwater AC Electrical and Acoustic Fields
Proceedings of the International Symposium on Fishways '90
We conducted studies to evaluate the usefulness of AC electrical and acoustic fields for guiding downrunning American shad Alosa sapidissima into a fish bypass in the industrial canal at Holyoke Dam on the Connecticut River, Massachusetts, USA. Adults avoided 0.02 V/cm AC electricity in flume tests, but radio-tagged downrunners in the canal did not avoid a much stronger AC array (0.25 V/cm). The AC array was a temporary barrier to movement with nine radio-tagged fish taking 1-9 attempts to pass through the array. A high frequency acoustic field (161.9 kHz) elicited strong initial avoidance by downrunners and, if maintained for 24 h, it concentrated uprunners, but not downrunners. Swift current flow and rapidly moving fish probably caused behavioral guidance of downrunners to be only temporary.